Slide rule



Feb. 15, 1944. M. c. ANDr-:RsEN

SLIDE RULE Filed Dec. 2, 1941 2 Sheets-Sheet 1 Inventor Attorney Feb.15, 1944. M. c. ANDERSEN SLIDE RULE 2 Sheets-Sheet .2

Filed Deo. 2, 1941 I u uentor @MMM Patented Feb. 15, 1944 UNITED STATESPATENT OFFICE SLIDE RULE Mads C. Andersen, San Benito, Tex.

Application December 2, 1941, Serial No. 421,337

l Claim.

The present invention relates to new and useful improvements in sliderules of the type comprising a runner, and has for one of its importantobjects to provide an instrument of this character comprising novelmeans for frictionally securing said runner in adjusted position.

Another very important object or the invention is to provide, in a sliderule comprising a pair of spaced, parallel outer bars and anintermediate bar slidable therebetween, unique means for securing saidouter bars together.

Other objects of the invention are to provide a slide rule of thecharacter described which will be comparatively simple in construction,strong, durable, highly efcient and reliable in use, compact, light inweight and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of theinvention will become apparent from a study of the followingspecification, taken in connection with the accompanying drawingswherein like characters of reference designate corresponding partsthroughout the several views, and wherein:

Figure 1 is a view in side elevation of a slide rule constructed inaccordance with the present invention.

Figure 2 is a view in end elevation of the instrument.

Figure 3 is a cross-sectional view, taken substantially on the line 3-3of Figure 1.

Figure 4 is a detail View in elevation of one of the end plates, lookingat the inner side thereof.

Figure 5 is a plan View of the device.

Figure 6 is a fragmentary View in vertical longitudinal section, takensubstantially on the line 6 6 of Figure 5.

Figure 'l is an enlarged detail View in cross section, takensubstantially on the line 'I-'I of Figure 6.

Figure 8 is a detail View in perspective of the spring pressed shoewhich frictionally secures the runner in adjusted position.

Referring now to the drawings in detail, it will be seen that theembodiment of the invention which has been illustrated comprises a pairof spaced, parallel outer bars I. Slidably mounted between the outerbars I is a double tongue intermediate bar 2. The bars I and 2 may be ofany suitable material. Further, the faces of the bars I and 2 may beprovided with any desired scales or combinations of scales.

The end portions of the outer bars I are rigidly secured togetherthrough the medium of pairs of plates 3 which are secured by fasteners 4on the sides of said bars. All of the plates 3 are identical and saidplates may also be of any suitable material. The intermediate portionsof the inner faces of the plates 3 are recessed, as at 5, to clear theslide bar 2 and the scales thereon. These portions of the plates 3 arefurther provided with finger receiving notches or recesses 6 tofacilitate gripping the end portions of the bar 2.

Slidably mounted on the bars I is a runner which is designated generallyby reference numeral l. The runner I includes identical plates 8 ofCelluloid or other suitable transparent material. The transparent plates8 include hair lines 9 to be read against the scales on the bars I and2.

Mounted between the end portions of the plates 3 are spacing blocks I0and II. Fasteners I2 secure the plates 8 to the spacing blocks I0 andII. As illustrated to advantage in Figure 7 of the drawings, thefasteners I2 comprise complemental male and female screws I3 and I4,respectively. The end plate fasteners 4 are similar to the fasteners I2.

The spacing block I0 has formed therein and extending from side to sidethereof a recess I5 for the reception of a shoe I6. The shoe I6 is ofany suitable material and comprises end portions Il of reduced thicknesswhich extend adjacent the end portions of the block I0. Coil springs I8yieldingly urge the shoe I6 against the outer edge of the adjacent barI. Sockets i9 are provided in the shoe I6 and in the block I0 for theriiception of the end portions of the coil springs It is thought thatthe manner in which the instrument is used will be readily apparent froma consideration of the foregoing. Of course, the slide 2 is adjustedlongitudinally relative to the bars I. As hereinbefore mentioned, therecesses 6 in the plates 3 facilitate gripping the end portions of theslidable bar 2. To adjust the runner l, it is only necessary to applysufficient force to said runner to overcome the frictional contact ofthe shoe I6, under the influence of the coil springs I8, with theadjacent bar I. The intermediate portions of the inner faces of thetransparent runner plates 8 are recessed, as at 2li, to clear the sidesof the bar 2 with the scales thereon. Certain of the holes in the plates3 and 8 are slightly larger than the respective fasteners 4 and I2 tofacilitate adjustment of said plates. In general, the construction andarrangement are such as to facilitate assembling and disassembling ofthe instrument.

It is believed that the many advantages of a slide rule constructed inaccordance with the present invention will be readily understood, andalthough a preferred embodiment of the instrument is as illustrated anddescribed, it is to be understood that changes in the details ofconstruction and in the combination and arrangement of parts may beresorted to which will fall within the scope of the invention asclaimed.

What is claimed is:

A slide rule runner comprising a pair of transparent plates for thereception of a rule therebetween, elongated spacing blocks between theend portions of said plates, one of said blocks having an elongated,longitudinal recess therein, a shoe slidable in the recess and includingreduced end portions extending between the end portions of said oneblock and the rule, the end walls of the recess being engaged with theshoe for securing said shoe against longitudinal movement, and coilsprings mounted in said one block and engaged with the shoe for pressingsaid shoe against the rule for frictionally securing the runner inadjusted position thereon.

MADS C. ANDERSEN.

